Recently, automation of loading and placing of goods on a pallet, that is, palletizing work, by using a robot has been frequently carried out. Originally, it was necessary to teach such a robot a series of work processes using an actual machine, that is, to cause the robot to hold goods, to actually load the goods on a real pallet, and prepare robot operation programs. However, the teaching using an actual machine took plenty of time and was cumbersome. Therefore, off-line teaching has prevailed, in which the operations of a robot are simulated on a computer to prepare robot operation programs.
Conventionally, in the off-line teaching of palletizing work made by a robot, many of parameters have been numerically inputted for respective goods, wherein the parameters correspond to position and direction (orientation), that is, at which part and in which direction goods are placed on a pallet.
Herein, based on FIG. 5, a description is given of a prior art technology. FIG. 5 is a plan view of a loading pattern.
In the prior art method, first, it was necessary that a plan view shown in FIG. 5 is prepared on sheets of paper. In the same drawing, 31 indicates a rectangular area whose length is L and width is L+2W and corresponds to a plan of a pallet. 32, 33 and 34 indicate a rectangle whose length is L and width is W, which correspond to a plan of goods to be loaded and placed on the corresponding pallet. The drawing shows that, first, goods corresponding to the rectangle 32 are placed on the corresponding pallet, goods corresponding to the rectangles 33 and 34 are placed thereon, thereby making a loading pattern formation to become H-shaped. Arrow 38 is a symbol indicating the directions of the rectangles 32, 33 and 34, wherein the arrow indicates the escape direction of a gripper claw of a hand which grasps the goods. That is, if previously placed goods exists in the direction of the arrow 38, the gripper claw is caused to interfere with the above goods. Thus, in order to determine a loading pattern, it is necessary to take care of the placing sequence and the direction of goods. After the loading pattern is determined on sheets of paper, it was necessary for an operator to code the loading pattern in the form of numerical data that can be read by the off-line teaching programs. The numerical data describe the pallet size and goods size in an appointed form, and describe the position and direction of the goods for each of the goods in the sequence of loading. An operator manually coded while reading the data from the previously prepared loading patterns.
However, in the prior arts, since data was manually coded on the basis of the abovementioned loading patterns after the loading patterns were manually prepared on sheets of paper, the work was very cumbersome. Also, since rules regarding construction and description of data are very complicated in coding the data, there was another problem, that is, that plenty of time was required for an operator to be acquainted with the coding work. In addition, still another problem arose in that, if there is an error in coding, the error cannot be easily found unless the data are read by the off-line teaching programs and the corresponding simulation is carried out.